This invention relates to thin-film magnetic transducers and more particularly to a plurality of thin-film transducer chips which are mounted on a magnetic flying head. The head is mounted adjacent a magnetic storage medium having a plurality of closely spaced tracks. Each of the transducer chips has a transducer adjacent a corresponding one of each of the tracks of the storage medium so that a plurality of transducers may be used for reading or writing on each of the tracks of the magnetic storage medium.
In high speed data processing systems data is stored on magnetic tape or magnetic disks for retrieval and use at a later time. It is important that large quantities of data be stored as compactly as possible to minimize the number of reels of tape or the number of disks used with the data processing system. It is also important that data be located on the magnetic medium and retrieved as quickly as possible while the data is being processed. In order to do this, magnetic disks may use a large plurality of tracks of data with a transducer positioned over each of the tracks. Such transducers must be very small when a large number of tracks are used and yet these transducers should produce a comparatively large signal so that noise in the system will not interfere with the data being retrieved. In some prior art systems a flying head carrying a read/write transducer head is positioned over the tracks. The output signal from these prior art transducers is relatively low and the lower frequency response is limited. In these prior art systems the flying heads must be repositioned each time it is desired to read or write information on any of the tracks of the magnetic recording medium.
Other prior art systems use a plurality of flying heads each having a plurality of ferrite read/write transducers. Each of these read/write transducers may be aligned with the other transducers so that the tracks served by one flying head interleave with tracks served by the other flying heads. For example, when three flying heads are used, the first head has transducers over tracks 1, 4, 7 etc., the second head has transducers over tracks 2, 5, 8 etc. and the third head has transducers over tracks 3, 6, 9 etc. If each head has 20 transducers the heads must be repositioned when more than 60 tracks are used on the storage medium.
In the prior art systems using read/write transducers and a disk as a storage unit the disk must complete one revolution after information is written on the medium before this information can be read and checked. This requires a relatively long period of time.
The present invention alleviates some of the disadvantages of the prior art by using thin-film inductive transducers to write information on the tracks of the magnetic storage medium and uses thin-film magnetoresistive transducers to read information from each of the tracks on the magnetic storage medium. In the present invention both the thin-film magnetic transducer and the thin-film magnetoresistive transducers are mounted on the same magnetic flying head so that information can be recorded on a portion of the medium as the disk moves under the inductive write transducer and can be read and checked as this same portion of the medium moves under the magnetoresistive read transducer. The read transducer may be mounted adjacent the write transducer so that the time between "writing" and "reading" is relatively short.
These thin-film transducers may be relatively small so that several hundred transducers may be formed across each inch of the flying head. Rows of these transducers may be positioned adjacent the disk so that information can be written on all of the tracks which are under the flying head transducers without moving the flying head. This increases the speed of data storage and retrieval.
The inductive write transducer and the magnetoresistive read transducer for each track can both be formed on a single substrate to facilitate aligning the write transducers with the read transducers for each of the tracks of the magnetic medium.
It is, therefore, an object of this invention to provide a magnetic flying head having a plurality of thin-film transducers for each track of a magnetic recording medium.
Another object of this invention is to provide at least one separate read transducer and one separate write transducer for the same magnetic track with both transducers being mounted on the same flying head.
A further object of this invention is to provide a flying head covering a plurality of tracks with each track having a plurality of thin-film transducers.
Still another object of this invention is to provide a flying head having a thin-film read transducer and a thin-film write transducer fabricated on the same substrate.